This project concerns the development of new clinical methods for the evaluation of physical properties of both detrusor and vesical neck and to a lesser extent detrusor contractility. Rapid cystometry allowed to develop a mechanical model for the calculation of viscous and elastic coefficients which were found to depend upon the amount of collagen relation to muscle present in the bladder. This test will be performed in patients presenting various types of bladder pathology. Coefficients will be correlated to data obtained from two methods: biochemical determination of collagen through quantitations of hydroxyproline, and in-vitro stretch-relaxation study. Surgical specimens obtained from the vesical neck will be processed through the two latter techniques and correlated with clinical data obtained from uroflowmetry (coefficient of flow rate acceleration), urethral pressure measurement of vesical neck compliance and a new device made for quantitation of urethral and vesical neck passive resistance. Standardization of these methods should provide more accurate clinical methods for the evaluation of both detrusor and vesical neck pathology.